Plugging device



April 7, 1970 R. F. SHORES 2 PLUGGING DEVICE Filed June 15, 1967 so I4 50 2 \W /I2 2 3;, 100 34v 50 INVENTOR. RAY F. SHORES ATTORNEY United States Patent 3,504,420 PLUGGING DEVICE Ray F. Shores, 1930 Searles Road, Baltimore, Md. 21222 Filed June 15, 1967, Ser. No. 646,405 Int. Cl. 1323p 19/02; B65d 39/12 US. Cl. 29-235 5 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Field of the invention This invention relates to expansible closures or plugs and more particularly to an expansible closure and manipulative tool for use in closing various apertures situate within machinery such as found in automobile power and drive systems.

Description of the prior art As a result of the present high volume or mass production techniques employed by industries engaged in multiple component assembly, there exists a continuing and increasing need for improvements in plugging or closing techniques. Particularly in the automotive industry, economic considerations favor the introduction of closing devices which retain the attributes of reliability and integrity over reasonable periods of usage while also being inexpensive to fabricate and install. Combining these attributes in the development of the ideal closure has been seen to be a somewhat difiicult task. One approach to the problem has led to the use of expansible plugs.

Expansible plugs as have heretofore been introduced to the industry have been seen to be eifective as replacement plugs for the threaded openings of crankcases. These openingsare characterized in being readily accessible to automotive servicing personnel. Accordingly, the plugs are readily inserted using conventional tooling. Formed or molded from a chemically inert expansible material such as neoprene, the plugs are stretched to lessen their diameter, inserted partially through the port, and then relaxed to expand and fill the opening. These plugs as have been offered to industry to date, however, are hindered by their relatively higher unit costs and by the delicacy of technique required in expanding and positioning them. For instance, the structure of typical expansive plugs is arranged such that prior to their insertion, a bolt or the like is threaded through an internally seated nut situate within a shoulder of the plug. The progression of the bolt axially through the shoulder causes an internally forced elongation and consequent diminution of the diameter of the insertable portion or shank of the plug. Structurally, the requsite positioning and presence of the aforesaid internal nut renders the shoulder portion of the plug somewhat delicate. Should excessive torque be imposed upon the elongating nut, the structural integrity of the shoulder, and consequently, that of the entire plug is jeopardized. When damaged, the embedded nut arrangement renders the plug most frustrating to remove and offers the most unwanted possibility of casting off a severed plug shank portion into an automotive crankcase or the like.

The necessity of applying a somewhat lengthy twisting action to the expanding bolt of the plug arrangement contributes an assembly time consumption factor generally unacceptable to mass production techniques. In addition to the above-noted time consumption arising from bolt rotation, mass assembly with the plugs would also require special and relatively expensive tooling requiring torque limiting controls. Further, once factory installed, in positions where servicing access is relatively difficult, the requirement for re-threading a small bolt into the plug to effect its removal becomes an undesirable and most frustrating task. The latter disadvantages has considerably hindered the universal acceptance of expansible plugs by industry.

Turning to the factors affecting the unit costs of manufacturing expansible plugs, where high volume production of such small parts is contemplated, a requisite to economy is the minimization of the number of separate components forming each plug. Additionally, the individual components must, of themselves, be of simple and easily mass fabricable dimension and shape. To the present, however, the plugs have been characterized by the required intra-molding of relatively elaborate stamped and formed metal parts. These metallic parts, when positioned within the interior of the plugs are also exposed to deteriorating chemicals, moisture and heat deriving from the general nature of their ambient environment.

In addition to lowering the unit cost of fabricating-the plugs themselves, it is also necessary that they be installable with a minimum of manual effort and dexterity. For instance, should factory labor be required to twist an installing tool through numerous revolutions, the cost of installation would approach prohibitive rates. Similarly,

should installation tooling be elaborate, use of the plugs tends to the impractical.

Certain of the expansible plugs now present in the market incorporate installation arrangements integrally within the plug bodies. While requiring a minimal of installation labor effort, these devices are precluded from high and volume practical use as a result of their intricacy and attendant high unit costs.

An additional requisite to acceptance by both industry and servicing agencies is the design capability of expansible plugs to be installed at relatively isolated points within complex machinery. Such isolated positions are often encountered in the differentials of automobiles. Accordingly, the plugs should desirably be removably mounted upon an installation tool which is fashioned of long and slender dimension. To be practical, however, this tooling must also be simple and inexpensive. All such installation tooling is preferred to be of such low cost'as to avail its use to all walks of the mechanics trade.

SUMMARY OF THE INVENTION component parts, is amenable to lowered unit cost production techniques. In one preferred embodiment, the plug device of the invention is fashioned so as to incorporate two parallel slots situate beneath the inter-molded metallic washer within the shoulder portion. These slots are adapted to receive the insertable tines of a corresponding fork implement, which is, in turn, in attachment with a placement tool.

The invention also encompasses a placement tool of remarkably simple design. The tool, fashioned having a simple, reciprocal cable plunger, is adapted by virtue of the aforementioned fork implement, to removably retain a plug for facile placement and insertion within an intended aperture. The combination of the inexpensive placement tool or implement with the correspondingly simple expansible plug provides a desirable arrangement amenable to high volume industrial use. Additionally, as a result of the simple and inherent design of the placement tool, the plug shoulder is assured of proper seating against the surrounding face surface of an aperture to be plugged. The placement tool may be readily fabricated of relatively long and slender dimension, thereby affording positioning access to remote points within complex machinery.

The placement tool and expansible plug combination retains the further desirable attribute of requiring an unvarying hand pressure for extending the plug shank portion during the insertion procedure. This uniformity of manual manipulation lends itself to high quality control industrial requirements.

In another preferred embodiment, the plug shoulder is adapted to removably connect to the placement tool through the use of a simple bayonet joint connection. This form of union readily lends itself to use within relatively inaccessible areas.

It is another object of the invention to provide an expansible plug in which the internal cavity of the plug structure may be inexpensively closed by the facile insertion of a simple insert member.

These and other objects and advantages of the invention will become apparent from the following detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a perspective view of an expansible plug fabricated in accordance with the invention along with a placement tool adapted for use with the plug device.

FIGURE 2 is a cross-sectional view taken along a plane passing through the longitudinal axis of the plug of FIGURE 1.

FIGURE 3 is a bottom view of the plug device of FIGURE 1 with portions broken away to reveal internal structure.

FIGURE 4 is a partially perspective and partially sectionalview respectively of the placement tool and plug of the invention showing the relative positions of their components during the procedure for plug insertion.

FIGURE 5 is a sectional view of the plug and placement tool of the device showing the positions of their components following the plug insertion procedure.

FIGURE 6 is a perspective and partially broken away view of a second embodiment of the invention.

FIGURE 7 is a sectional view of a second embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The plug and placement tool of the invention offer a straightforward solution to the earlier described problems by being fashioned from a minimal number of component parts. These parts lend themselves to low cost production techniques by virtue of their basic and noncomplex form.

Structure Referring to FIGURE 1, a plugging device manufactured in accordance with the present invention includes an expansible plug shown generally at 10 adapted for removable attachment to the end portion of a placement tool shown generally at 12. The expansible plug 10 is fabricated from a suitable expandable and heat resistant material such as neoprene or the like and is configured having a shoulder 14 to which is integrally molded an expansible neck portion or stepper 16. Shoulder 14 is also formed having keyways or slots 18 and 20 disposed therein for removable attachment with the tool 12. Small integrally molded sealing rings or ridges 22 protrude from the work contact face of shoulder 14.

Turning to FIGURES 2 and 3, the internal structure of the expansible plug is revealed in its unextended state. The plug is formed having a singular, uninterrupted right cylindrical bore or passage 24 extending through the shoulder portion 14. Passage 24 leads into the hollow interior 26 of the expansible neck 16 at the apex of which may be disposed a bearing plate 28 fashioned of metal or a hard surfaced plastic. Surrounding the passage 24 there is molded within the shoulder 14 a simple, planar washer or annular disk 30 disposed within a plane parallel to the inner and outer faces of shoulder 14. As may be evidenced from the drawing, the slots 18 and 20 are rectangular in cross-section, positioned on the internal or contact face side of the washer 30 and are mutually parallel. Shown beneath the passage 24 is a cylindrical hard plastic closure 32 adapted for optional insertion within the passage following the placement of plug 10 into an opening.

Looking to FIGURES 1, 4 and 5, the structure of the placement tool 12 and its relation to plug 10 is illustrated. The tool 12 is formed having a tubular body structure 34, the forward end of which is press-fitted, soldered or brazed to an end cap 36. Tube 34 is closed at its rearward end by a threadedly attached end cap 38. Reciprocally mounted within the tube structure 34 and extending through suitable bores in both end caps 36 and 38 is a plunger rod 40. The rod 40 terminates rearwardly in a plunger handle 42 and its forward end or head 44 is formed to assume the shape of a smooth hemisphere. A helical compression spring 46 is positioned about the rod 40 and Within tube 34 in a manner biasing the rod 40 rearwardly. Spring 4-6 nests against the inner surface of end cap 36 and is selected so as to urge the rod 40 outwardly by pressure against a stop plate 48 fixed to the rod 40. The plate 48 is slideable within tube 34 and serves the additional function of limiting the travel of the plunger head 44. Also connected to the forward end of tube 34 at cap 36 is a fork shaped plug retaining implement 50 bent in a U-shape and having two parallel tines 52 and 54. Times 52 and 54 are parallel, extend over the end cap 36 at either side of its central bore and are proportioned so as to readily slide into the slots 18 and 20 of plug 10. Optionally mounted near the rearward end of tube 34 is a finger grip 56 which serves to allow one handed operator manipulation of the placement tool.

Operation The neck portion of the plug 10 is designed and selected so as to have an initial, unextended diameter slightly larger than the opening into which it is to be fitted. Upon selecting a plug 10 of appropriate size, the plug is slipped across the forward cap 36 of tool 12. In so positioning the plug, tines 52 and 54 readily slip within the corresponding slots 18 and 20 within shoulder 14. Thusly situate upon the tool 12, the bottom face of shoulder 14 abuts against the outward face of cap 36. The combined tool and plug assembly is then manipulated so as to cause the movement of the plunger rod 40 into the hollow neck interior 26 thereby causing both its elongation and diametric contraction. The relative positions of the components of the plugging device at this stage are depicted in FIGURE 4. As may be evidenced from that figure, the positioning of the lower planar face of the plug shoulder 14 against the end cap 36 assures the vertical alignment of passages 24 and 26 with rod 40.

Upon insertion of the neck 16 through a hole situate in a workpiece as at 100, handle 42 is released to allow the diametric expansion of the neck. This expansion serves to cause the sealing of the hole to be plugged and is depicted in FIGURE 5. Following re-expansion, the tool 12 is removed by shifting it laterally thereby causing the removal of the tines 52 and 54 from slots 18 and 20. Where desired, the top hat plug 32 may then be inserted into the passage 24 to close off the internal structure of the plug.

As will be apparent from the description and drawing, the presence of the washer or annular reinforcement 30 serves to add necessary rigidity to the shoulder 14 during the insertion step of elongating the neck 16. Where repeated removal and insertion of the plugs is contemplated, the bearing plate 28 affords protection against wear. In most instances, however, the smooth hemispherical head 44 of rod 40 will be found not to harm the tip of the neck 16.

Where plugs are to be installed in positions of difficult access, the tool 12 may be fashioned having an extended tube 34. Thusly extended, the tool 12 assumes long slender dimension universally desirable for such tasks.

Alternate embodiment In applications wherein access to plugs or holes to be plugged is particularly restricted, the embodiment of the invention illustrated in connection with FIGURES 6 and 7 will be found of value. As may be observed in FIG- URE 6, the placement tool in this approach is identical in all respects with the device earlier described except for the structure of the plug retaining implement. The latter is now modified to comprise bayonet insert prongs 64 which jut from the end cap 62 of body tube 60. Prongs 64 are arranged such that they will connect with or disconnect from a plug upon the exertion of a slight twisting motion. The latter is accomplished by alteration of the plug structure as illustrated in FIGURE 7. As evidenced from the figure, washer like reinforcement member '76 is modified by the stamping therein of insert grooves or openings 78. By inserting the prongs 64 through the shaped openings 72 and 74 within shoulder 70', the plug will be adequately held in position upon the place-ment tool for extending the neck portion 80.

It will be apparent that no lateral movement of the tool is required during the procedure for attaching the tool to the plug in the alternate embodiment. The plug structure as modified, however, still retains the advantage of incorporating only a simple washer-shaped internally molded reinforcement. Consequently, the unit costs of producing the device are held advantageously low without sacrifice to reliabilit or strength.

As may be evidenced from the foregoing, the plugging device of the invention, by virtue of its simple but reliable and inexpensive structures lends itself to a broad spectrum of uses. It will be apparent to those skilled in the closure arts that many variations may be made in the detailed disclosure set out herein without departing from the spirit or scope of the invention.

I claim:

1. A plugging device comprising:

(a) an expansible plug formed having (1) a shoulder portion having a planar rearward face,

(2) an expansible hollow neck portion formed integrally with said shoulder portion and axially aligned therewith perpendicularly to said planar rearward face,

(3) a passageway in axial alignment with said neck portion communicating between said shoulder portion and said hollow interior of said neck 6 portion,

(4) keyway means disposed within said shoulder portion and comprising at least two slots extending axially inwardly from said shoulder portion rearward face,

(5) annular rigid reinforcing means disposed within said shoulder portion and parallel with said rearward face and having grooved portions registering with said keyways; and

(b) a placement tool for removable attachment to said expansible plug for insertion and removal of said plug comprising (1) a plunger rod mounted for reciprocal motion,

and

(2) retainer means insertable within said plug keyway means in such a manner that when said retainer means is inserted said plunger rod is in substantial axial alignment with said passageway of said expansible plug, said retainer means being adapted to engage said grooved portions of said rigid reinforcing means.

2. The plugging device of claim 1 in which said placement tool retainer means comprises at least two prong members slidably insertable within said slots so as to provide a twistably engageable bayonet joint connection with said grooves within said rigid reinforcing means.

3. A plugging device comprising (a) an expansible plug formed having (1) a shoulder portion formed as a right cylinder and having a planar rearward face,

(2) an expansible hollow neck portion formed integrally with said shoulder portion and axially aligned therewith perpendicularly to said planar rearward face,

(3) a passageway in axial alignment with said neck portion communicating between said shoulder portion and said hollow interior of said neck portion,

(4) annular rigid reinforcing means disposed within said shoulder portion and parallel with said rearward face,

(5) keyway means disposed within said shoulder portion and comprising at least one slot disposed within said shoulder parallel with said rearward face and situate between said reinforcing means and said neck portion; and

(b) a placement tool for removable attachment to said expansible plug for insertion and removal of said plug comprising (1) a plunger rod mounted for reciprocal action,

(2) retainer means insertable within said plug keyway means in such a manner that when said retainer means is inserted said plunger rod is in substantial alignment with said passageway of said expansible plug.

4. The plugging device of claim 3 in which:

(a) said reinforcing means is planar and washershaped; and

(b) said placement tool retainer means includes at least one fork tine slidably engageable with said keyway.

5. The plugging device of claim 3 in which there are two keyway slots formed within said shoulder so as to have a rectangular cross-section and disposed in spaced relationship therein so as to extend parallel therethrough and permit said passageway to pass between them.

References Cited UNITED STATES PATENTS 429,579 6/1890 Oliver 21552 2,533,715 12/1950 Conklin 220-245 3,307,731 3/ 1967 Seltzer 220-245 2,095,272 10/ 1937 Vandcrhoof 21554 FOREIGN PATENTS 64,066 3/ 1913 Germany.

ROBERT C. RIORDON, Primary Examiner J. C. PETERS, Assistant Examiner US. Cl. X.R. 

